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Many
people do not understand the importance of the following the appropriate
steps to prepare an engine to run for the first time. The steps are
very important, and can mean life or death for a high performance
engine (no kidding). The information in this article can also be a
useful guide to starting an engine that has been sitting for a long
period of time, since it ensures proper oiling before the engine
fires.
Engine
Assembly
Use good quality
engine oil (20-50 or 30 weight) to coat all bearing surfaces, as well
as the surfaces of moving parts they contact. Use an oil treatment
(e.g.: STP) for camshaft lobes and the heads of the lifters, and engine
oil for the sides of the lifters. We prefer Torco cam lube, and supply
it will all our camshafts.
In your oil
pump, lube the gears up with STP or a HEAVY oil. This assures a good
oil pump prime (it's very thick; make sure the brand you use is the
SAME as the oil you plan on running, so they are compatible), so you
will not crank your engine for 30 minutes trying to achieve oil pressure.
Keep your spark plugs out until later; if they are in, remove them.
The reason the spark plugs are removed (or left out) is that you do
not want the connecting rod or main bearings "loaded" during the "dry"
period that exists before oil pressure is achieved. It is only after
oil pressure is achieved that the spark plugs should be in place during
cranking.
If you have
stock valve springs on your engine, you can assemble your engine completely,
but this is not the case for an engine with a hot cam, which should
have heavy duty valve springs. These engines must be cranked for oil
pressure without their pushrods installed, since we don't want to
wipe off the cam lube while we are cranking for oil pressure!
Lubricate valve
stems and valve guides with engine oil (many people use white grease,
or something else, but I don't think this is a good idea. Grease can
keep the engine oil OUT, and galling can occur from lack of lubrication).
After all, engine oil is what all these parts use to live a long life
later on, so let's use what works!
Prepare
to Run!
Install the
engine into the vehicle or onto your engine stand, and get prepared
to crank it over. REMOVE THE SPARK PLUGS AND OIL PRESSURE SWITCH.
If you have a T-4, you can just remove the spin on oil filter. Next,
crank the engine over until oil squirts out the oil pressure switch
hole (or the oil filter bracket on the T-4). Re-install the oil pressure
switch (or oil filter, which you have filled with oil), and connect
the oil pressure switch wire. Crank until the light goes out then
continue cranking for another 10 seconds or so. The oil system of
the engine is now ready.
Set the ignition
timing on the engine (you do know how to do this without running the
engine, right?) to the proper setting for the distributor you are
using, and install the spark plugs and plug wires. Install the pushrods
if you have not done this yet, and adjust the valves to .008" (better
loose until things settle in). Hydraulic lifter engines can adjust
them to 1 ½ turns tighter than "zero" clearance. Make sure you have
fuel pressure, and fire it up!
Running
the Engine!
This next step
is VERY IMPORTANT! Immediately bring the rpm's up to 2500 or higher.
I vary the rpm's between 2500 and 4000, and do this for 15 minutes
while keeping your eyes glued to the oil light! A second person back
at the engine looking for oil or fuel leaks is a REALLY good idea
too, since you don't want a fire or Valdez in your driveway! Most
oil leaks will occur very soon after startup, if at all. Now, this
is a nerve-racking experience to have the engine (it sure seems loud!)
at these rpm levels when it's NEW, but if everything is OK, it's going
to be fine. Remember that this engine is not even under a load, so
it's not a big deal.
After the 15
minutes has elapsed, shut down the engine, and change the oil and
adjust the valves. When you fire the engine up this time, you can
let the engine idle, and make the needed carburetor adjustments. Drive
the car easy, and change the oil and adjust the valves again after
100 miles or so.
Now that the
"bearing break in" is done, you want to REALLY heat the engine up
by driving it hard! This loads the rings and will break the pistons,
cylinders, and rings in together. I have found that engines that are
missing the flaps or thermostat assembly have a tough time seating
the rings in, and the only cure for this (my experience) is to get
the engine HOT (some of these engines "never" break in). Find a hill
and drive full throttle up the thing a few times, in a gear that loads
the engine down a bit. The loading and extra heat burns the glaze
off the cylinders and allows everything to seat together well. I do
not feel a longer "break in" period is needed (some say 10,000 miles)
other than getting the rings seated, and this can be done in 500 miles.
Repeat the
oil change/valve adjustment at 500 miles, and then resume your normal
maintenance schedule (which hopefully does not mean oil changes every
15K miles, and/or valve adjustments once a cylinder or two goes dead
at idle).
Now
for some explanation!
The reason for the varying
of engine rpm at initial start up is that the VW flat four engine does NOT adequately
oil the camshaft lobes and lifter heads at rpms below 2500. The oil for the cam-lobes
comes from oil sprayed off the connecting rods! If the engine is run below 2500
rpm for too long, the cam and lifters do NOT break in together properly (since
they don't get enough oil) They get enough oil for running, but not break-in.
In addition, you also run the risk (the higher valve spring pressures you run,
the higher the risk) of one or more of the cam lobes getting scored and even going
flat. Some engine builders (myself included) will run the engine on one set of
valve springs for break in, and change to the competition springs (really heavy)
after the cam and lifters are broken in. The cam and lifters must work together
under a moderate load (valve springs), to allow the metal to work harden before
extreme loads are placed on them. This oiling quirk is also the reason for cranking
the engine for oil pressure with no valve spring pressure on the camshaft (no
pushrods, remember?). With really heavy valve springs, just this cranking alone
can damage the cam if racing spring pressure is present!
Maintenance
Schedule
Schedule oil changes
every 1000 miles (no filter), and every 3000-5000 if a filter is present. The
oil strainer (stock VW) does NOT count as a filter, and in fact I remove it on
engines that turn over 6000 RPMs! I have seen more engine failures caused by this
strainer than I care to count (even on stock engines), so I leave it out and change
oil religiously. One more thing! The new strainers that are available are of a
much more corse "mesh" than the originals, so any "filtration"
is minimal. The addition of a magnetic drain-plug is a good idea! I adjust valves
to .006" every 3K miles (it does not take long, nor is it difficult) on old engines,
and every 500 miles (until adjustments settle down) on newer engines. Keep a record
of valve clearances at every valve adjustment; when a valve gets "abnormally
tight" compared to the rest of them for 2-3 valve adjustments, it's a warning
sign that the vavle is stretching and is ready to fail! Valve job time ( and replace
exhaust valves)!
Enjoy and take
care of your new engine, and it will take care of you.

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